Abstract: On November 22, 2008, Employee #1, an operator of a John Deere 650J Track Dozer with a front blade attachment, was working at a concrete and aggregate batch yard, located adjacent to active public vehicular traffic lanes, in a highway work zone construction project. Witnesses saw the dozer traveling in reverse, towards the highway, without an operator. Employee #1 had apparently been operating the dozer, but investigators could not determine how or why he dismounted the dozer. Witnesses last saw Employee #1 running along the right side of the moving dozer, making several attempts to remount it. Just before the dozer hit a concrete traffic barricade (traffic delineator device) that separated the batch yard from the highway, Employee #1 apparently slipped and was run over by the right-side dozer track. The dozer climbed the barricade and came to rest on top of it. Employee #1 was killed in the accident.